[Radio Wrangler]

An interesting thing about noise is that we can now buy active devices whose noise contribution at room temperature is less than the contribution of an ideal resistor at cryogenic temperatures.

Why would anyone bother if the source impedance of a signal source has a resistive component contributing much more noise at room temp?

Well, antennae aimed above the horizon can see a satellite signal (or something astronomical) against a much colder background temperature, and their resistive source impedance can source noise at near a 3 Kelvin level when their direction coincides with a quiet part of the sky.

I expected this thread to cover cryogenically treated valves, but cryo-treated Kit-Kats? I suppose if you have an unusual process, the temptation is to try it on everything to hand. How else are discoveries made? In this case I'll believe the audible difference!

David